Glossary

Alkaline soils, also known as sodic soils, belong to the category of problem soils. This is because they have a basic limiting factor for plant growth, a factor which, depending on its level, makes it correspondingly prohibitive to use these soils for the cultivation of any plant. This factor is the alternative Na+, which due to its high concentration degrades the chemical and physical characteristics of the soil and has a toxic effect on plant growth, making the soil an unsuitable environment for crop growth.

They are also called heavy soils. This group includes soils in which the percentage of clay is at least 35%, although in many cases this percentage is more than 45%. They are soils with a high capacity to retain moisture and nutrients and are difficult to cultivate. Drainage and aeration problems are often encountered and root development in the soil is hampered. They are difficult to treat when there is a lot of moisture, because they are very water permeable and muddy quickly. This makes their surface impervious to air so that the soil quality is degraded and plant growth is hindered.

According to the Convention on Biological Diversity signed in Rio in 1992, biological diversity or biodiversity means the diversity of living organisms of all origins including, inter alia, terrestrial, marine and other aquatic ecosystems and ecological complexes of which they are part. It also includes diversity within species, between species and between species and ecosystems. More simply, biodiversity is defined as the diversity of life in all its forms (plants, animals, fungi, etc.) and at all levels of organisation (genes, organisms, ecosystems). The different plants, animals and micro-organisms, the genes they contain and the ecosystems they form. Thus, the term “biodiversity” embraces all life on Earth.
Biodiversity is necessary to sustain life on Earth. Its real value is immeasurable, as it enables all living organisms to adapt to a changing environment. Biodiversity is vital to the health and well-being of the world’s population.

Calcareous soils have a calcium content of over 40%, are well aerated and are rich in humus and nutrients. They are fairly fertile but do not retain much water. With good irrigation, barley and legumes can be grown on such soils.

A carbon footprint (or greenhouse gas footprint) is a calculated value or index that makes it possible to compare the total amount of greenhouse gases that an activity, product, company or country adds to the atmosphere.
A product’s carbon footprint includes the emissions for the entire life cycle. These run from the production along the supply chain to its final consumption and disposal. Similarly an organization’s carbon footprint includes the direct as well as the indirect emissions that it causes.

Chill hours are the period of low temperatures that many fruit tree species need during the winter to break dormancy and be able to flower and germinate in the spring.

They are also called soils of medium composition. This group includes soils where the proportions of sand, clay and silt are approximately equal. Soils in this group manifest only the desirable properties of sand and clay. As a result, an average mechanical composition is considered suitable for plant growth without problems.

The clay-calcareous soils are the most fertile soils of all. Their pores hold a lot of water. They were formed by the accumulation of valuable, nutrient-rich materials at the end of the last ice age. The most demanding plants thrive in such soils.

The farmer can see how his crop grows within specific time intervals by two factors: the degree days and the chill hours.

With the degree days, the farmer can compare different plots or growing seasons and understand in which cases they will have an early or late crop. And accordingly, he can better organise his work to save valuable time.

Earth observation can be defined as the collection of information about physical, chemical or biological systems using remote sensing technologies such as satellite sensors or airborne instruments, but complemented by field observations and other recording techniques. Earth observation is used in the agricultural sector because it can assess and visualise over time and at multiple scales, usually using indicators, crop processes and properties. These indicators are derived through modelling processes, using data from sensors, field measurements and records describing farming activities at farm level. These models need to be tested over time in order to make the necessary corrections and check their adequacy for the specific crop type, variety, soil type and microclimate conditions.

Growing degree days show, in simple terms, how many hours of temperature a plant has “accumulated”. The more hours, the faster the plant will grow.

The European Union provides farmers with income support or “direct payments” to: function as a safety net and make farming more profitable; guarantee food security in Europe; assist them in the production of safe, healthy and affordable food; reward farmers for delivering public goods not normally paid for by markets, such as taking care of the countryside and the environment.

Farmers generally receive income support based on their farm’s size in hectares. All EU countries have to offer a basic payment, a payment for the climate, environment and animal welfare to promote sustainable farming practices (eco-schemes). As it is compulsory for EU countries to provide these payments, they are often referred to as obligatory payments. Eco-schemes are obligatory for EU countries to provide to farmers, but voluntary for farmers.

Additionally, EU countries can choose to offer other payments that focus on specific sectors or types of farming. There are specific schemes designed to provide further help to small and medium sized farms, young farmers, farmers who operate in areas of natural constraint and/or sectors undergoing difficulties.

Leaf wetness (LF), or more simply the amount of water drops on leaves, gives a sense of how favourable the environmental conditions are for the growth of specific fungi on plants.

Although organic deposits are more limited than other types of topsoil, they occupy a significant part of the land surface and are important from an environmental and agricultural point of view. Organic deposits are most commonly formed in coastal marshes and terrestrial swamps. Where the water is shallow, characteristic flora species such as bogs, reeds and common grass are found. In Greece, reeds, rushes and willows grow in such areas, e.g. in the Prespes region. As these plant organisms die or shed their leaves, a layer of organic debris is formed on the bottom. Due to the presence of water, these organic residues do not oxidise and, over the years, they accumulate and form thick organic deposits. They are particularly suitable for growing rye, potatoes and grassland.

The reference evapotranspiration (ETo), in simple terms, shows the daily water loss from a given plot if it were covered with grass (reference crop).

With the ETo index, each producer can know which day or week his crop needs more or less water.

Saline soils are found all over the world and are mainly formed under the influence of dry or semi-arid climatic conditions and high temperatures. They are characterised by the presence of free soluble salts, which may often be present on the surface of the soil in the form of a thin surface layer. The accumulation of salts in soil is a phenomenon that has been occurring since time immemorial. It has created and continues to create serious problems with regard to the efficient use of soil, due to the degradation of its productivity. Today, huge areas of land all over the world are put out of cultivation every year because of extensive salinisation and the consequent deterioration in productivity. This problem is becoming more acute over time.

Fertilisers increase the salt concentration of the soil solution or the salinity index of the fertiliser. The salinity index is the ratio of the osmotic pressure from the addition of some fertilisers to the osmotic pressure developed by applying the same amount of NaNO3. In general, fertilisers with a higher nutrient content have a lower salinity index. Nitrogen and potash fertilisers have a higher salinity index and are more detrimental to germination than phosphate fertilisers.

They are also called light soils. This group includes soils in which the percentage of sand is more than 70% and the percentage of clay is less than 15%. Generally speaking, these soils are dominated by the properties of sand. That is, they have a low capacity to retain moisture and nutrients and cultivation practices are easily carried out. The movement of air, water and root growth in the soil is unimpeded. Sandy soils must be adequately irrigated and fertilized rationally with frequent and small doses. Very poor sandy soils are used only in forests (pine forests), while richer sandy soils (with a higher percentage of clay) are used for rye and potatoes. Soils where the percentage of sand is not overwhelmingly greater than that of clay are also found and are therefore classified as sandy soils.

The telemetric stations continuously record the progress of the crop with sensors that collect data from the soil, air and plant, to provide smart and effective advice and accurately calculate the environmental footprint of the crop. They are installed within the crop, at the height of the plant foliage, and accurately record the microclimate and soil conditions within the field. The data collected feeds scientific models of disease and insect prediction, nutrition and irrigation.

Agro-meteorological stations are an evolution of telemetric stations, since, in addition to data on crop progress, they also collect weather-related data and can thus provide a more complete picture of a field and a crop.

By looking at the satellite images and the data from the Normalized difference vegetation index (NDVI) and watching how it changes in each plot during the growing season, the farmer can identify problems in plant growth.
In other words, he can quickly and simply understand if something is wrong with a part of the crop so that an on-site inspection can be planned in time, and also to determine the presence of weeds during the period when the fields sown with annual crops are uncultivated.

The satellite takes a new image every 5 days. With these satellite images and the vegetation index, one can easily and quickly see how “lively” one’s field is. Thus: the greener the colour in the satellite image, the more the index value increases and approaches 1. The more yellow and towards brown the colour, the smaller the value of the indicator and the closer to 0.

Therefore, if any variation in colour is observed in more than one image during the growing season, then there is likely to be a problem and it is worth an on-site inspection.